Does choline in the gut, which is metabolically processed to form the neurotransmitter acetylcholine, plays a vital role in the axis? If so, can any form of choline be taken orally, or does it have to be CDP Choline?

Choline is an essential nutrient that is important to neurodevelopment and neurotransmission as well as liver function and general metabolism. Most choline metabolism occurs in the body’s tissues. Acetylation of choline to the neurotransmitter acetylcholine occurs primarily in brain. Choline is also oxidized to betaine and phosphorylated to phosphatidylcholine. Dietary sources of choline include eggs, beef, salmon, cauliflower, Brussel sprouts, and breast milk. Dietary choline is more bioavailable than choline in supplements. Both choline and CDP-choline supplements are available and good sources for choline. Oral CDP-choline is absorbed and releases cytidine and choline into the blood stream to reach body sites including the brain. According to National Health and Nutrition Examination Surveys (NHANES) results dietary supplements had a nutritional benefit and reduced deficiencies in key nutrients including choline. Choline’s role in lipid metabolism is linked to energy balance, weight loss and obesity. Recently choline deficiency has been linked to Alzheimer’s disease.

Gut microbiota can also metabolize choline. One of the key metabolites of dietary choline is trimethylamine which is oxidized to trimethalamine N-oxide (TMAO) in the liver. L-carnitine is also a dietary source of TMAO. Metabolism of choline and L-carnitine resulting in high levels of TMAO has been linked to risk of cardiovascular disease.

This question was answered by Jane Foster, PhD